﻿266 
  REPORT 
  UNITED 
  STATES 
  ENTOMOLOGICAL 
  COMMISSION. 
  

  

  Schiner's 
  statement 
  that 
  the 
  larvae 
  live 
  parasitically 
  in 
  pupae 
  of 
  Lepidop- 
  

   tera, 
  and 
  records 
  the 
  breeding 
  of 
  A. 
  cephus 
  and 
  A. 
  fur 
  from 
  the 
  nest 
  of 
  

   a 
  Texan 
  mud- 
  wasp, 
  which 
  he 
  referred, 
  with 
  a 
  question, 
  to 
  Pelopceus, 
  but 
  

   which, 
  as 
  we 
  have 
  ascertained 
  from 
  an 
  examination 
  of 
  the 
  mud 
  tubes 
  

   which 
  are 
  deposited 
  in 
  the 
  Cambridge 
  Museum 
  of 
  Comparative 
  Zoology, 
  

   belong 
  to 
  Trypoxylon. 
  We 
  have 
  similar 
  cells 
  from 
  Texas 
  and 
  other 
  

   parts 
  of 
  the 
  South. 
  They 
  differ 
  from 
  those 
  of 
  Pelopceus, 
  in 
  being 
  

   wider, 
  ribbed 
  on 
  the 
  upper 
  surface, 
  and 
  fastened 
  not 
  only 
  side 
  by 
  side 
  

   but 
  in 
  long 
  tubes 
  end 
  to 
  end. 
  The 
  Pelopceus 
  spins 
  a 
  thin, 
  yielding, 
  semi- 
  

   transparent, 
  elongate 
  cocoon 
  of 
  a 
  golden-brown 
  color, 
  with 
  more 
  or 
  less 
  

   loose 
  silk 
  around 
  it 
  and 
  the 
  tail 
  end 
  thickened 
  and 
  docked; 
  the 
  Try- 
  

   poxylon 
  spins 
  a 
  tougher, 
  thicker, 
  more 
  solid, 
  and 
  smooth 
  cocoon 
  of 
  a 
  dull, 
  

   dark 
  brown 
  color, 
  generally 
  about 
  half 
  as 
  long 
  as 
  the 
  other 
  (but 
  varying 
  

   greatly 
  in 
  size), 
  and 
  with 
  the 
  head-end 
  often 
  expanding 
  into 
  a 
  flange. 
  

  

  We 
  have 
  reared 
  what 
  is 
  very 
  near 
  to 
  and 
  probably 
  identical 
  with 
  

   Argyramceba 
  fur 
  from 
  larvae 
  that 
  had 
  preyed 
  on 
  Trypoxylon 
  albitarse 
  

   which 
  had 
  made 
  use 
  of 
  the 
  mud 
  cells 
  of 
  Pelopceus 
  lunatus, 
  or 
  the 
  common 
  

   mud-dab, 
  in 
  Texas 
  ; 
  also 
  from 
  the 
  same 
  wasp 
  that 
  had 
  made 
  use 
  of 
  the 
  

   burrows 
  of 
  a 
  bee 
  (Anthophora 
  abrupta 
  Say). 
  The 
  larva 
  of 
  Argyramceba 
  

   has 
  very 
  much 
  the 
  same 
  appearance 
  as 
  that 
  of 
  Systcechus 
  and 
  Triodites 
  

   and 
  the 
  pupa 
  is 
  distinguished 
  from 
  the 
  pupa 
  of 
  this 
  last 
  (PL 
  XVI, 
  Figs. 
  

   5, 
  5 
  a), 
  principally 
  by 
  its 
  longer 
  and 
  more 
  numerous 
  hairs, 
  longer 
  anal 
  

   spines, 
  and 
  more 
  conspicuous 
  spiracles. 
  

  

  The 
  discovery 
  of 
  the 
  " 
  parasitism 
  " 
  of 
  these 
  Bee-flies 
  upon 
  the 
  locust 
  

   eggs 
  at 
  once 
  suggests 
  a 
  comparison 
  with 
  the 
  similar 
  diversity 
  of 
  para- 
  

   sitic 
  habits 
  among 
  the 
  Meloidce, 
  as 
  given 
  in 
  our 
  First 
  Keport, 
  some 
  of 
  them 
  

   infesting 
  Bee-cells, 
  while 
  others, 
  as 
  the 
  true 
  Blister-beetles 
  (Lyttini) 
  feed 
  

   on 
  locust 
  eggs. 
  

  

  The 
  Anthracids 
  are 
  now 
  united, 
  by 
  the 
  best 
  authorities, 
  with 
  the 
  Bom- 
  

   byliidce, 
  of 
  which 
  family 
  as 
  a 
  whole 
  Osten 
  Sacken 
  has 
  said 
  i 
  3 
  ' 
  05 
  They 
  are, 
  

   "perhaps, 
  the 
  most 
  characteristic 
  and 
  one 
  of 
  the 
  most 
  abundantly 
  rep- 
  

   resented 
  families 
  of 
  Diptera 
  in 
  the 
  western 
  region, 
  including 
  California." 
  

   The 
  abundance 
  of 
  blister-beetles 
  is 
  also 
  well 
  known 
  to 
  characterize 
  this 
  

   region, 
  and 
  we 
  have 
  shown 
  how 
  this 
  abundance 
  is 
  connected 
  with 
  the 
  

   abundance 
  of 
  locusts. 
  It 
  is 
  of 
  interest, 
  therefore, 
  to 
  find 
  that 
  the 
  Bee-flies 
  

   bear 
  a 
  similar 
  relationship 
  of 
  parasitism 
  to 
  the 
  latter, 
  and 
  that 
  the 
  

   characterization 
  of 
  the 
  fauna 
  in 
  these 
  two 
  groups 
  is 
  really 
  dependent 
  

   upon 
  the 
  presence 
  of 
  the 
  locusts 
  as 
  well 
  as 
  upon 
  the 
  rich 
  representation 
  

   of 
  the 
  burrowing 
  Hymenoptera. 
  

  

  With 
  these 
  general 
  remarks 
  we 
  will 
  now 
  give 
  a 
  more 
  full 
  and 
  descrip- 
  

   tive 
  account 
  of 
  the 
  two 
  bee-flies 
  which, 
  by 
  rearing 
  from 
  the 
  }arva, 
  we 
  

   know 
  to 
  have 
  this 
  locust-egg-feeding 
  habit. 
  

  

  Systcechus 
  oreas. 
  

  

  The 
  character 
  of 
  the 
  eggs 
  and 
  the 
  manner 
  in 
  which 
  they 
  are 
  laid 
  have 
  

   not 
  yet 
  been 
  observed. 
  The 
  larva 
  (PI. 
  XVI, 
  Fig. 
  1) 
  has 
  already 
  been 
  

  

  a3S 
  L. 
  c, 
  p. 
  225. 
  

  

  